In a loop of custom post type, display first custom taxonomy term

A little bit more involved but:

<?php

function get_single_term($post_id, $taxonomy) 
{
    $terms = wp_get_object_terms($post_id, $taxonomy);
    if(!is_wp_error($terms))
    {
        return '<a href="'.get_term_link($terms[0]->slug, $taxonomy).'">'.$terms[0]->name.'</a>';   
    }
}

//example
echo get_single_term(5, 'category');